Means for drying and pulverizing coal



Sept. 9, 1930. w, RUNGE ET AL MEANS FOR DRYING AND PULVERIZING COAL Filed Jan. 15. 1926 1 VENTOR ATTORNEYJ Patented Sept. 9, 1935' UNITED. sr T-ss PATENT oFrIc-E warren-Runes, .or near omen," 'rmw assent, mm A; racmn, *or' YONKERS, nnw.YonK,- AssIGNoRs 'ro mrnnmrronsn comwsrron memnnmne oonronarron, or rmwzonx, N, 1., a conrom-rroerorpnrswannp ms :03 name up: mvmame .ippllcationflled January This invention relates to the d 'ng of materials, and is particularly use for the sqf' 1' the of coal, the invention is ('5 especially usefu in. assistance ior preparing and pulveri'zingcoal to be burned in .pulverized coal burmng installations, such as stationary boiler installations, low temperature distillation apparatus, and the like The inventlon will be described in connection with the preparation plant of a pulverized coal burmng boiler'ins tallation.

It is the primary object of the invention to provide a simple andeiiective means for I drying the coal, whether. it be the coal tobe' supplied to the pulverizer, or whether itlbe the coal which has been pulverized. a

How the foregoing, together'witli such objects as may hereinafter appear,-or are incident to our invention, are realized is illustrated in the accompanying drawing, where- 1n'-- .Thefigure is a diagrammatic illustration of a pulverized coal 'preparin plant or ashown in section.

The raw coal, which is usually prelimie narily crushed in a s stem of this character, is stored in the bin from which it is fedof regul'able feeder, to the conveyor pipe 9, which pipe discharges to a cyclone separator 10. The coal is conveyed throu h the pipe 9.

by means of a blast, preferab y a blast of.

85 hot flue as set up by the-fanll. A pipe 12 leads I mass 14: to the'intake of the fan 11. The heat for drying the coal is supplied by. the heat of this flue gas. The flue gas andcoal-enter so ti The arewithdrawn from the it beingYdesirable to -recirculate the M upon the valve 12 may stationary boiler, the boiler urnace eing by a star *feederB, or other well known type.-

om the stack 13 of the boiler fur the ecyclone separator wherein the coal is '1s,-1eae..[seria 1 in. a m,

cyclone separator 10 and. returned to the intake :sideof the fan bymeans oi the pipe-18,

ases :under some conditions, in which event esh flue gas could only be supplied through the pipe 12= inter1nittently, or which purpose such pipe'fis provided with a valve '12". -A

- vent, 19 is also provided for the cyclone separator to vent an excess gas in this portion 'ofthe system,t is-vent bein led to the (to stack, or any other suitable point, depending presence or absence of dust particles therein. P a i It may be desirable-totem r the flue'gas with air in order to regulate t e temperature If"? ,-'thereof, to which endwe provide a pi'pe 20 f W opening into the pipe 12 or supplying airf to dilute the'flue gasfthe amount of air be- 1 ing controlled bythe valve 21, lnasmuchjas the coal ma be fairly dryat times, in fact,'7 'sufliciently asto not need an drying, the

kept closed, an the valve 21 open, in which case the carrying blast will com osed of 'air entirely.

To a 0rd additional control over temperarture, we-providea pipe22-leadihgfrom the ,stacklat agmint beyond the econoinizer 23to 1 the pipe 1 thepipe 22 being controlled by a -valve 22. The pipe -12leads from thestafckin advance of the'economi'zer (which maybe anairpreheater, forfexample), and, there 4 fore, supplies much hotter as than would be suppliedthrough-the'pi e 2 Thereforegby. proper manipulation o the-valves 12*. and

22 and 21,-any desireddegree of temperature inay be obtained. I I linw'aase herethe coal need ete dried at all',-'or may only needs small; amount ,of' drying, [it will. be unnecessary tofpass the mill through the cyclone separator,'o r part of v l the coal may be supplied dlrectly to'the mill,

eoal, or all of the coal, through the. cyclone f separator 10, and we,therefore,provide a. by

and part indirectly through the cyclone separator.

The coal which has been pulverized in the mill 16 is lifted by an air blast created by the fan 26 into the cyclone separator 27, where the carrying air is unloaded of the coal. The air is returned to the mill through the return pipe 28, and the separated coal may be discharged from the cyclone separator 27 directly to the furnace, or to an intermediate bin, or the like. When the coal is not very wet, the drying may be done in the mill and in the cyclone separator 27, in which. event the coal would be carried by a hot blast through the pipe 9 to the mill, this hot blast constitutinga portion of the carrying medium for carrying the pulverized coal from the mill 16 to the cyclone separator. In such practice, a portion of the gas will be taken from the return pipe 28 by means of the pipe 29, the hot gas used to introduce the coal to the mill replacing the amount drawn off, whereby the moisture content in the system is kept down, and a drying action occurs in. the mill, and in the cyclone separator 27.

Obviously, coal which has been pulverized, and which may be moist, can-be dried by carrying it' through a cyclone separator in a hot blast, in accordance with our invention.

What we claim is ,l. In a pulverized coal burning system, a

furnace having an ofi-take for the waste gases, a source of supply of raw coal, a mill, a cyclone separator intermediate the source of supply and the mill, a. conduit leading from the se arator to the mill, and means for creatingfa last of flue gas for carrying the raw coal to the separator.

2. In 'a pulverized coal burning system, a furnace having an oif-take for the waste gases, a source of supply of raw coal, a mill, a cyclone separator intermediate the source of supply and the mill, a conduit leading from the se arator to the mill, and means for creating a last of flue gas for carrying the raw coal to the separator, togetherwith means for diluting the flue gas with air.

3. In combination, a pulverized fuel burning furnace having an off-take for the waste gases, an economizer in said off-take, and means for utilizing flue gas comprising a fuel drying and transportin system including connections for taking 0 flue gas in advance and behind the economizer, said connections being controlled by valve means whereby the temperature of the flue gas used in the system may be regulated.

4. In combination, a mill, a source of supply of raw coal, a cyclone separator, a connection from the source of supply to the separator, a by-pass from the source of supply to the mill, andmeans whereby said separato1 discharges to the mill.

'5. In combination, a pulverized coal burning furnace having an ofl-take for the waste CERTIFICATE or CORRECTION Patent No. 1, 775, 324. I Granted September 9, 1930, to

WALTER RUNGE ET AL.

It is hereby certified that error appears in the printed specification of the 7 above numbered patent requiring correction as follows: Page 2, lines 67, 72, 74 and 75, claim 5, before the word "separator" insert the word cyclone; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st, day of October, A. D. 1930.

v v M. J. Moore, Acting Commissioner of Patents.

(Seal) CERTIFICATE OF CORREGTIQN.

Patent No. 1,775,324. v Granted September 9, 1930, to

WALTER RUNGE ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, lines 67, 72, 74 and 75, claim 5, before the word "separator" insert the word cyclone; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the ease in the Patent Ottiee.

Signed and sealed this 21st day of October, A. D. 1930.

J. Moore, (Seal) Acting Commissioner of Patents. 

